Date: 5/5/25 6:39 am From: Abram Fleishman <abfleishman...> Subject: Re: [MBBIRDS] This year's migration numbers/lateness
Hi Carol and Pete,
The historical lines on birdcast come from the 1995-2017 period. As with
any average, there are high years and low years and the average draws the
line through the middle. There may even be average years that the line
represents really well. But I like to think about our rainfall in Santa
Cruz county (or California in general) when thinking about this stuff. With
our rainfall, we normally have wet years or dry years and both of which are
quite far from the average rainfall. Only occasionally do we get years that
hit the average.
I imagine the same thing is happening with bird migration. There are many
contributing factors like the previous breeding season’s reproductive
success, the fall migration and then winter survival rate, and then spring
migratory corridor and survival. All these are affected by weather (storms
can kill, but rains lead to strong food resources, winds and storms can
push and pull birds during migration) along with a host of other factors.
This is all just to say that averages are just one piece of info, to ask
the question of how this year stacks up to past year we would need to seem
more data. Specifically yearly values or trend lines.
On Mon, May 5, 2025 at 00:48 Carol Pecot <carol.pecot...> wrote:
> Good thoughts, Pete, thanks. Thanks also for mentioning the 7 simple
> actions link, it is a good one! Jane Orbuch made some posters in a larger
> format, and we usually display them at birding events. On the topic of
> planting natives = more caterpillars = more baby bird food, Doug Tallamy’s
> Homegrown National Park park is awesome:
> https://homegrownnationalpark.org/.
>
> By the way, this coming Saturday will be a small Migration event at
> Natural Bridges. If anyone is interested in helping in some way, please
> contact me.
>
> Carol
>
>
> > On May 4, 2025, at 9:59 PM, Pete Sole <pete...> wrote:
> >
> > Hi Carol,
> >
> > I'm no expert. I don't know how far back the "historic" data goes. But
> my suspicion, is that data older than perhaps 10 or 20 years, reflects
> migration patterns that may no longer be present. That is why when I look
> at data on ebird to try to tease out trends, I try to limit the data to the
> last 10 years. If nothing else, we know that land use and climate patterns
> have changed significantly in the last 50 years. Not to mention the
> estimates, that we have lost some 2.9 billion birds in North America since
> 1970. (source: https://www.birds.cornell.edu/home/bring-birds-back)
> >
> > Regardless, here are 7 suggestions to help avian species:
> >
> > https://www.3billionbirds.org/7-simple-actions > >
> > My 2 cents,
> >
> > Pete
> >
> >
> > On 5/4/25 8:57 PM, Carol Pecot wrote:
> >> I was looking at the BirdCast dashboard (
> https://dashboard.birdcast.info/region/US-CA-087) and saw that the graph
> of the “Total Birds Crossed” seems to show about 1/2 the number of birds
> compared to the historic amount for our county. Does that seem correct, or
> might that be a late migration that people have been mentioning? If late
> is the case, then maybe it will continue rising more steeply…?
> >>
> >> Does anyone have other information on this?
> >>
> >> Carol Pecot (We now have M & F BH Grosbeaks, and got a Wilson’s
> Warbler about a week ago)
> >>
> >
>
> --
> You received this message because you are subscribed to the Google Groups
> "mbbirds" group.
> To unsubscribe from this group and stop receiving emails from it, send an
> email to mbbirds+<unsubscribe...>
> To view this discussion visit
> https://groups.google.com/d/msgid/mbbirds/<5F57E0A0-9444-4F26-B8D6-3F9B6B99C496...> > .
>
